Transport of sup 3 H-estradiol-17. beta. -(. beta. -D-glucuronide) (E sub 2 17G) in basolateral plasma membranes (bLPM) from male rat liver

Conference · Fri Mar 15 00:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5242235

Vore, M; Ganguly, T; Hoffman, T ^[1]

---

1. Univ. of Kentucky, Lexington (United States)

E{sub 2}17G is a naturally occurring, cholestatic metabolite of estradiol which is transported into isolated hepatocytes by an organic anion carrier system. In order to characterize its transport properties more fully, bLPM were isolated according to Meier et al. Uptake of 1 {mu}M E{sub 2}17G into bLPM was temperature dependent with an initial rate of 4 pmol/mg protein/6 sec at 37C. E{sub 2}17G uptake was decreased with increasing media osmolality, indicating uptake into closed vesicular space. However, extrapolation of equilibrium values of infinite osmolality yielded a positive intercept indicating that about 50% of E{sub 2}17G was bound. Neither an out > in Na{sup +} gradient, an in > out Cl{sup {minus}} gradient nor an in > out OH{sup {minus}} gradient stimulated E{sub 2}17G uptake. Addition of {alpha}-ketoglutarate ({alpha}KG) to the extravesicular media did not stimulate E{sub 2}17G uptake in the presence of a NA{sup +} gradient. In isolated hepatocytes, replacement of NaCl and NaNO{sub 3} in the media significantly decreased E{sub 2}17G uptake, whereas replacement with Na gluconate increased uptake, suggestive of electrogenic E{sub 2}17G uptake. These data indicate that the driving forces for E{sub 2}17G uptake differ from that for bromosulfophthalein, sulfate and cholate.

• OSTI ID: 5242235
• Report Number(s): CONF-9104107-; CODEN: FAJOE
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 5:5; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ESTRADIOL
METABOLISM
METABOLITES
MEMBRANE TRANSPORT
CELL MEMBRANES
LIVER
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BODY
CELL CONSTITUENTS
DIGESTIVE SYSTEM
ESTRANES
ESTROGENS
GLANDS
HORMONES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
MAMMALS
MEMBRANES
ORGANIC COMPOUNDS
ORGANS
RODENTS
STEROID HORMONES
STEROIDS
VERTEBRATES
550501* - Metabolism- Tracer Techniques